Apparatus for ore concentration.



y A. H. HIGGINS & w. w. STENNING.

APPARATUS FOR ORE CONCENTRATION.

APPLICATION men NOV. 12. 1913.

1,1'55,8l5, Patented Oct. 5, 1915.

Wi'fnessesl J Inwmors. I

TED SA; s orrror...

ARTHUR HOWARD HIGGINS AND WILLIAM WARWICK STENNING, OF LONDON,

ENGLAND, ASSIGNORS TO MINERALS SEPARATION LIMITED, OF LONDON,

ENGLAND.

APPARATUS ron one CONCENTRATION.

a for example in previous United States Pat- -ents No. 835,120, to Sulman, Picard & Ballot,

of November ,6, 1906, No. 962,678 to Sulman,

Greenway & Higgins, of June 28, 1910, and No. 1,064,723 to Greenway & Lavers, of

June 17, 1913, and also for carrying out the process of differential flotation as described for example in previous United States Patent No. 1067 185 to Nutter & Lavers, of July 15, 1913.

Hitherto it has been the common practlce to introduce the ore pulp (with the agents necessary for froth formation) into an agitation vessel where the pulp was subjected to violent agitation accompanied by the beating in of the supernatant air after which the pulp (containing a potential froth) was discharged into a separate spitzkasten in which the froth floated and was separated.

One object of this invention is to provide an ap aratus in which agitation, aeration, froth ormation and froth separation are effected in one box or series of boxes without requiring the use of spitzkasten.

A further object is to remove the froths immediately they are formed so that a mineral-bearin froth ready for flotation shall not be sub ected to further agitation with the pulp.

An incidental object is to effect the eflicient. recovery of so-called f tender .froths from which the mineral has a tendency, to shower.

An apparatus for concentrating ores by aseous flotation of certain mineral particles in liquid'accor'ding to this invention comprises the combination with an upright ves-' sel having means for introducing an ore plup and means for withdrawing residues (preferably at or near the bottom), of means for introducing air or other gas at or near the bottom of the vessel, means for violently agitating and aerating the pulp near the bot- Speciflcation of Letters Patent.

Application filed November 12, 1913. Serial No. 800,441.

tom of the vessel, means for maintaining the pulp comparatively still near the top of the vessel and means for removing mineral-bearing froth from the top of the vessel.

, One practical form of the apparatus com prises the combination of an upright vessel (preferably rectangular) having an inlet for ore pulp and an outlet for residues, a horizontal centrifugal agitator near the bottom of the vessel, an air inlet pipe leading into the bottom of the vessel below the agitator and one or more baffles above the agitator so arranged as to provide a comparatively quiescent zone near the top of the vessel where. the froth forms and is separated.

If desired the top of the vessel or vessels may be constricted so as toconduct the froth to a comparatively small outlet at'the top.

The constricted portion may, if desired, be

provided with bafiies. This arrangement may especially be employed where the mineral has a tendency to fall out of the froth.

The air inlet is preferably at the center of the bottom of the vessel so that the air is drawn in by the rotation of the agitator, but the air inlet may be eccentric or a jet of air may be blown in at the bottom in such a way as to assist agitation, or the air may be introduced by a steam injector.

' The accompanying drawing is a diagram in perspective illustrating by way of ex-' ample one method of carrying this invention into effect. I v

A preliminary mixing box A is provided with an agitator B carried on a rotatable vertical spindle B At the top is a conduit C for the introduction of ore pulp and vessels D provided with taps D for the introduction of froth-forming agents such as oil, acid, etc. Connected to the center of the bottom of the box and below the agitator is an air inlet conduit E. The outlet for the pulp is a slot F in the discharge side of the 'box, partly covered by a plate F The prelimi nary mixer as a matter of fact, may be of any convenient form and forms no part of this invention. For example, it may be re-' partition-s H. Each vessel has an air inlet pipe E leading to the center of the bottom of the vessel. A horizontal rotatable agitator B is arranged near the bottom of each vessel mounted on a vertical rotatable spindle B The inlet for pulp to each vessel is the slot F which is partly covered by the directing plate F. At the right-hand side ofthe figure, the plate F is shown broken away so as to make the form of the inlet conduit F more clear. The agitator may be a Howard agitator as described in United States Patent No. 1,084,210, issued January 13, 1914, or a plain four-blade agitator as shown at'B on the right-hand side of the figure orany other arrangement for producing violent turbulence can be employed and such device is hereinafter referred to as the centrifugal agitator.

Above the agitator and inclined. downwardly from the inlet side to the outlet side which passes over the overflow lips N of the vided between the two baffles.

is a 'baflie J which confines the violent turbulence mainly on its underside and which extends completely down to the outlet side but not completely up to the inlet "side. The spindle B passes through this battle.

A second baffle K is arranged above the first baffle and is inclined downward a short distance fromthe inlet side of the vessel. The two baflles may if desired be spaced apart by divisions L, or a number of divisions in the form of a grid L may be pro- Above these baflles the space in the vessel constitutes a quiescent zone where the froth forms, and a launder M is provided to catch the froth vessels. Above the lowest point of the baffle J an outlet. conduit is formed to lead the residues into the next vessel. This is the conduit F already described. The object of the curved directing plate F is to insure that the action of the centrifugal agitator shall tend to draw in the pulp from the precipitating vessel and not to drive it back.

The operation of the apparatus is as follows :The ore pulp containing the agents necessary for froth formation enters the first vessel G through the inlet conduit F, and the deflecting plate F directs the flow of pulp as required. The centrifugal agitator B is rotated at a very high speed, say 1200 revolutions per minute,'and the pulp is subjected to violent agitation. One action of the agitator is to draw in air through the air inlet pipe E and this air serves for the aeration of the pulp upon which the subsequent froth formation depends. The whole of the pulp passes upwardly under the inclined baffle J and -meeting the upper ,baffie K, is deflected down on the upper side of the baflie J (thus for example the agitated and aerated pulp 'may .come through the openlngs of the g1'id's.L At this stage the pulp is comparatively still and the minof spitzkasten, it is to be understood where for example a very coherent froth is produced, with a tendency to include gangue, one or more spitzkastens may be employed in place of the launder M, for example a continuous open spitzkastenmay be used as described in the previous United States patent to Broadbridge and Howard No. 1,081,196, issued January 13, 1914:.

It will be seen that the single unit of the ore concentration apparatus embodying this invention consists of a vessel in which there is an inlet for air or other gas near the bottom, a zone of violent aeration and agitation near the bottom and a comparatively quiet zone near the top where the mineralbearing froth forms and is separated. lit is within this invention to vary the means for introducing air, the form and nature of the means for producing the violent agitation and aeration, the form and nature of the baffles or other means for creating a comparatively quiet zone distinct from the zone of turbulence, and the means for introducing the pulp and removing the froth and the residue. 1

What we claim as our invention and de-' sire to secure by Letters Patent is 1. Apparatus for concentrating ores by gaseous flotation of certain mineral particles 'in liquid comprising, in combination, a vesfsel, the baflle being inclined downwardly from the inlet side to the outlet side of the vessel, an inlet for the pulp to the vessel below the bafile, means for removing the froth from the upper surface of the liquid, and an outlet for the residues above the baflle. I

2. Apparatus for concentrating ores by gaseous flotation of certain mineral particles in liquid comprising, in combination, a. vessel, means for introducing a gas therein at the lower part of the vessel, means for producing a zone of violent agitation and gasi fication in the lower part of the vessel, a baflie above the agitator for producing a quiescent zone in the upper part of the vessel, the baffle being inclined downwardly from the inlet side to the outlet side of the vessel, a second bailie to direct the agitated and gasified pulp into the quiescent zone above the first mentioned baflie, an inlet for the pulp to the vessel below the baflie, means for removing the froth from the upper surface of the liquid, and an outlet for the residues above the baffle.

3. Apparatus for concentrating ores by gaseous flotation of certain mineral particles in liquid comprising, in combination, a series of contiguous vessels each having means for introducing a gas therein at the lower part of the vessel, means for producing a zone of violent agitation and gasification in the lower part of the vessel, a baflie above the agitator for producing a quiescent zone in the upper part of the vessel, the baflle being inclined downwardly from the inlet side to the outlet side of the vessel, an

, inlet for the pulp to the vessel below the v to the vessel below the baffle, means for rebafile, means for removing the froth from the upper surface of the liquid, and an outlet for the residues above the baflie, the inlet to each vessel except the first of the series being also the residues outlet of the next contiguous vessel in advance.

4. Apparatus for concentrating ores by gaseous flotation of certain mineral particles in liquid comprising, in combination, a series of "contiguous vessels each having means for introducing a gas therein at the lower part of the vessel, means for producing a zone of violent agitation and gasificaw tion in the lower part of the vessel, a baflie above the agitator for producing a quiescent zone in the upper part of the vessel, the

bailie being inclined downwardly from the inlet side to the outlet side of the vessel, a

second bafiie to direct the agitated and gasified pulp into the uiescent zone above the first mentioned ba e, an inlet for the pulp moving the froth from the upper surface of the liquid, and an outlet for the residues above'the baflie, the inlet 'to each vessel except the first of the series being also the sel, a centrifugal agitator near the bottom of the vessel, a bafile above the agitator 'and inclined downwardly from the inlet side to the outlet side of the vessel, an inlet for the pulp to the vessel below the bafiie, a second baflle to direct the agitated and aerated pulp into a quiescent zone above the baflie where and an outlet for the residues above the baflie at its lowest point.

6. Apparatus for concentrating ores by gaseous flotation of certain mineral particles in liquid, comprising, in combination, a series of contiguous angular vessels each of which has an air'inlet pipe leading to the center of the bottom of the vessel, a centrifugal agitator near the bottom of the vessel, a baffle above the agitator and inclined downwardly from the inlet side tothe outlet side'of the vessel, an inlet forthe pulp to the vessel below the baffle, a second baflle to direct the agitated and aerated ulp into a quiescent zone above the'first baffle where the froth forms, means to remove the froth, the inlet to each vessel except the first of the series being also the residues outlet of the ARTHUR. HOWARD HIGGINS. WILLIAM WARWICK. STENNING.

Witnesses:

WILLIAM H. BALLANTYNE, ERNEST W. Moss.

sel of the series above the first baflle thereof the froth forms, means to remove the froth I next contiguous vessel in advance and being 

